My son is really into the PBS show, Dinosaur Train, so for his 4th birthday he wanted his cake to be Buddy the T-Rex from the show.
All of the cakes were made from scratch. The base was a marble, the body was chocolate, and the head was vanilla. I filled all of the layers with a chocolate fudge butter cream. The arms were made with rice crispy treats.
I needed to build a stable structure so that the head wouldn't topple over. I fitted two pieces of plywood (1 large for the base, 1 small for the head) with threaded floor flanges. I then fitted the cake board over the large piece of plywood and screwed in a length of PVC pipe (wrapped in saran wrap).
The base of the cake and the body were then stacked onto the PVC pipe. This was then crumb-coated with butter-cream and left to set while I worked on the head. The vanilla cakes were stacked onto a shaped piece of cardboard and shaped into the dinosaur's head. This was also crumb-coated with butter-cream. After this set, I made indents to form the mouth and eye sockets.
Once the cakes were set, I made homemade marshmallow fondant. The body and head were covered separately in orange MM fondant. Then I placed the head on the small piece of plywood the I had glued the shaped cardboard to, and screwed that onto the top of the PVC pipe.
After the structure was complete, I made teeth and fingernails from white mm fondant and "glued" them with water to the hands and mouth; the eyes were balls of mm fondant secured in place with cut skewers. The detail of the eyes and the diamonds on the head and body were made from thinning food coloring and painting it on the fondant.
This was the most engineered cake that I have made yet, and my son and his friends thoroughly enjoyed it.